Chemical composition of essential oils in Zataria multiflora Boiss. from different parts of Iran and their radical scavenging and antimicrobial activity

The objective of the study was to characterize the chemical constituents, antioxidant and antibacterial properties of five ecotypes of Zataria multiflora Boiss. essential oil with respect to main phytogeographic grown towns in Iran. Our investigation showed that the plants had essential oil yield ranging from 1.59 ± 0.86% to 0.99 ± 0.29% v/w. There were qualitative similarities among the oils from different origins, whereas the amounts of some components were varied. From different samples, 34, 34, 32, 29 and 53 various compounds were identified, representing 98.32%, 97.77%, 99.5%, 98.38% and 96.54% of total oils, respectively. The highest oxygenated monoterpens value in this study stood at 72.99%. Moreover, thymol, a phenolic compound of oxygenated monoterpens, was the most abundant component in GC/MS ranging from 27.05% to 64.87%. In the DPPH antioxidant assay, all samples exhibited a remarkable activity with a higher degree of IC₅₀ = 19.7 ± 0.7 μg/ml almost similar to BHT (18.1 ± 0.4 μg/ml). Escherichia coli O157:H7 was the most resistant and Candida tropicalis was the most vulnerable organisms with MICs of 16 and 0.062 mg/ml, respectively. In conclusion, it seemed that geographical variation might have influenced the oil compounds either quantitatively or qualitatively.     

In vitro screening of essential oil from young and mature leaves of Artemisia scoparia compared to its major constituents for free radical scavenging activity

The present study investigated the chemical characterization, and antioxidant activity of essential oil hydrodistilled from young and mature leaves of Artemisia scoparia. GC–MS analyses revealed a monoterpenoid nature (64–67%) with 44 and 31 constituents in young and mature leaves oil, respectively. The oil from young leaf contained greater amount of oxygenated compounds. β-Myrcene (24.13%) and p-cymene (27.06%) were the major constituents in young and mature leaves oil, respectively. A. scoparia leaf oils (25–200 μg/ml) exhibited a strong 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity and antioxidant activity against hydroxyl radical and hydrogen peroxide. However, the activities of major constituent monoterpenes, β-myrcene and p-cymene, were less. In general, the DPPH radical scavenging and antioxidant activity was in the order: mature leaf oil > young leaf oil > β-myrcene > p-cymene.     

Chemical composition and antioxidant activities of the essential oil and methanol extracts of Psammogeton canescens

This study is outlined to probe the chemical composition of essential oil and in vitro antioxidant activity of the essential oil and methanol extracts of Psammogeton canescens. The chemical composition of the hydrodistilled essential oil of the aerial parts of P. canescens was analyzed by GC and GC/MS. The main constituents of the oil were found to be β-bisabolene (33.35%), apiole (28.34%), α-pinene (11.86%) and dill apiole (8.17%). Antioxidant activities of the samples were determined by three various testing systems namely DPPH, β-carotene/linoleic acid, and reducing power assay. In DPPH system, the highest radical-scavenging activity was seen by the polar subfraction of methanol extract (49.5 ± 1.21 μg/ml). Furthermore, in the second case the inhibition capacity (%) of the polar subfraction (92.40% ± 0.72) found to be the stronger one. However, in the reducing power assay, a reverse activity pattern more than in the first two systems was observed, and the essential oil was stronger radical reducer than was the methanol extract in all of the concentration tested. Our findings demonstrate that the essential oil and methanol extracts of P. canescens possess significant antioxidant activities and may be suggested as a new potential source of natural antioxidant.     

Chemical composition, antimicrobial and antioxidant activities of essential oil from Gnaphlium affine

The chemical composition of the essential oil from Gnaphlium affine was determined, and its antimicrobial and antioxidant activities were evaluated. Twenty-four compounds, representing 94.95% of the amount of total oil, were identified by gas chromatography-mass spectrometry (GC-MS) analysis. Main constituents of the essential oil were found to be eugenol (18.24%), linalool (10.62%), trans-caryophyllene (8.86%), α-terpineol (5.97%), p-cymene (5.75%), hexadecanoic acid (5.63%), γ-cadinene (4.98%), δ-cadinene (4.22%), α-humulene (3.22%), and (−)-β-elemene (3.15%). The essential oil revealed a remarkable antimicrobial effect against the tested food-borne microorganisms with the MIC and MBC values in the ranges of 0.2-1.56 μg/ml and 0.39-3.13 μg/ml, respectively. The essential oil showed a potent antioxidant activity in ABTS radical scavenging, lipid peroxidation and reducing power assay. It was suggested that the essential oil from G. affine may be a new potential source as natural antimicrobial and antioxidant agents applied in food systems.     

Study on chemical composition,anti-inflammatory and anti-microbial activities of extracts from Chinese pear fruit (Pyrus bretschneideri Rehd.)

Pyrus bretschneideri Rehd. belongs to the genus Pyrus, a member of Rosaceae family. It is a routine edible fruit, and also used as a folk medicine to treat cough, eliminate constipation, and relieve alcoholism. In order to clarify the active compounds of P. bretschneideri, the phytochemical study were performed. Five compounds were isolated and identified as 2β,19α-dihydroxy ursolic acid, quercitrin, dibutyl phthalate, diisobutyl phthalate and α-amyrin. Additionally, we investigate the anti-inflammatory and anti-microbial effects of the fractions of P. bretschneideri partitioned with petroleum ether, ethyl acetate and n-butanol, respectively. In the carrageenan-induced rat paw edema test, the EtOAc fraction showed the strongest inhibition of edema formation 0.5–5 h after edema induction, followed by n-butanol. EtOAc also displayed potent anti-inflammatory activity against xylene-induced ear edema (22.03% and 43.69%, respectively) and acetic acid-induced extravasation of Evan’s blue dye (39.58% and 49.92%, respectively) at the dose of 200 and 400 mg/kg. While, the anti-microbial results showed that ethyl acetate and n-butanol fractions exhibited strong activity against the bacteria strains. Moreover, 2β,19α-dihydroxy ursolic acid, α-amyrin and quercitrin could significantly inhibit the ear edema induced by xylene at the dose of 20 mg/kg, and exhibited moderate anti-microbial activities against the bacteria strains.     

Essential oil composition and antioxidant activities of Curcuma aromatica Salisb.

The chemical composition of the hydro-distilled essential oil from leaves of Curcuma aromatica Salisb. was analysed by GC–MS. Twenty-three compounds representing 94.29% of the total oil were identified. The antioxidant activities of the oil and various extracts of C. aromatica were evaluated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radical-scavenging assays. The oil and methanol extract showed potent DPPH radical-scavenging activities (IC₅₀ = 14.45 and 16.58 μg/ml, respectively), which were higher than butylated hydroxyanisole (IC₅₀ = 18.27 μg/ml). The extracts also exhibited remarkable superoxide radical-scavenging activities (IC₅₀ = 22.6–45.27 μg/ml) and the activity in the methanol extract was superior to all other extracts (IC₅₀ = 22.6 μg/ml). Furthermore, the amount of total phenolic compounds was determined and its content in ethyl acetate extract was the highest as compared to other extracts. The results indicate that the oil and extracts of C. aromatica could serve as an important bio-resource of antioxidants for using in the food industries.     

Essential oil composition and antioxidant and antimicrobial properties of the aerial parts of Salvia eremophila Boiss. from Iran

The essential oil composition and in vitro antioxidant and antimicrobial activity of the essential oil and methanol extract of Salvia eremophila were evaluated in this research. GC and GC/MS analysis of the plant essential oil resulted in the identification of 28 compounds representing 99.24% of the oil. Borneol (21.83%), α-pinene (18.80%), bornyl acetate (18.68%) and camphene (6.54%) were detected as the major components consisting 65.85% of the oil. The plant essential oil and methanol extract were also subjected to screenings for the evaluation of their antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene–linoleic acid tests. While the plant essential oil showed only weak antioxidant activities, its methanol extract was considerably active in both DPPH (IC₅₀ = 35.19 μg/ml) and β-carotene–linoleic acid (inhibition percentage: 72.42%) tests. Appreciable total phenolic content (101.25 μg/mg) was also detected for the plant methanol extract as gallic acid equivalent in the Folin–Ciocalteu test. The plant was also screened for its antimicrobial activity and good to moderate inhibitions were recorded for its essential oil and methanol extract against most of the tested microorganisms.     

Chemical composition,antibacterial and antioxidant activities of leaf essential oil and extracts of Metasequioa glyptostroboides Miki ex Hu

The aims of this study were to analyze the chemical composition of leaf essential oil of Metasequioa glyptostroboides Miki, and to test the efficacy of oil and extracts (hexane, chloroform, ethyl acetate and methanol) against food spoilage and food-borne pathogenic bacteria and their antioxidant activity. The GC–MS analysis revealed 49 compounds representing 94.62% of the total oil containing 2-butaneone (30.6%), cyclopentane (15.1%), β-myrcene (13.29%), cyclobutane (7.67%), furan (3%), valeramide (2.81%), borneol (1.2%), β-farnesene (1.67%), thymol (1.44%) and α-pinene (1.46%) as major components. The oil (1000 μg/disc), and extracts (1500 μg/disc) exhibited promising antibacterial effect as a diameter of zones of inhibition (10–18 and 7–13 mm), respectively. MIC values of oil and the extracts were ranged 125–2000 and 250 to <2000 μg/ml, respectively. Also the oil had strong antibacterial effect on the viable counts. Scanning electron microscopic study demonstrated potential detrimental effect of the oil on the morphology of S. aureus KCTC1916. The free radical scavenging activities of the oil and ethyl acetate extract were found to be 11.32 and 19.12 μg/ml, respectively. Also the ethyl acetate extract revealed the highest phenolic contents (85.17 mg/g of dry wt) as compared to the other extracts.     

Chemical compositions,antifungal and antioxidant activities of essential oil and various extracts of Melodorum fruticosum L. flowers

This research presents the chemical composition antifungal and antioxidant activities of essential oils and various extracts from Melodorum fruticosum flowers. The essential oil composition of M. fruticosum flowers were investigated by GC–MS with 88 identified volatile constituents. Phenyl butanone, linalool, benzyl alcohol, α-cadinol, globulol and viridiflorol were found to be the major components, respectively. The dichloromethane extract played a major role as a remarkable fungicide according to their inhibition action against all tested pathogens followed by hexane extract, essential oil and methanol extract, respectively, along with their respective MIC values ranging from 125 to 1000 μg/ml. The dichloromethane extracts were also evaluated to be superior to all extracts tested with an IC₅₀ value of 87.6 μg/ml whereas other extracts showed their IC₅₀ values ranging from 100.13 to 194.50 μg/ml.     

The antioxidative effect of Iranian Mentha pulegium extracts and essential oil in sunflower oil

The aim of the present study was to evaluate antioxidative activities of the essential oil, methanol and water extracts of Iranian pennyroyal in vegetable oil during storage. Different concentrations (0, 200, 400, 600, 800 and 1000 ppm) of essential oil, water and methanol extracts and beta-hydroxy toluene (BHT; 200 ppm) were added to sunflower oil emulsion in the presence of cupric ions and incubated for 7 days at 60 °C. Peroxide values (PVs) and thiobarbituric acid reacting substances (TBARS) levels were measured in each day up to day of seven. Furthermore, antioxidant capacity of the essential oil and extracts were determined using DPPH and β-carotene–linoleic acid methods. Values were compared among groups in each incubation time points using ANOVA. Results showed that DPPH and β-carotene–linoleic acid assay findings on the Mentha pulegium extracts were comparable to those found on BHT. Furthermore, in all incubation time points, M. pulegium extracts lowered PVs and TBARS levels when compared to the control (p < 0.001). In this respect, water extract was more potent than the methanol extract. Essential oil did not show considerable antioxidative effect. It seems that water extract of M. pulegium is a potent antioxidant which makes it as a potential antioxidant for oil and oily products during storage.     

Antioxidant and antidermatophytic activities of essential oil and extracts of Metasequoia glyptostroboides Miki ex Hu

This study was undertaken to assess the antioxidant and antidermatophytic potential of the essential oil and extracts (hexane, chloroform, ethyl acetate and methanol) of Metasequoia glyptostroboides Miki ex Hu. Antioxidant activity was evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The free radical scavenging activities of the oil and ethyl acetate extract were found to be superior (IC₅₀ = 9.1 and 14.24 μg/ml, respectively) as compared to butylatedhydroxyanisole (BHA), (IC₅₀ = 18.27 μg/ml). Also the ethyl acetate extract revealed the highest phenolic contents (93.26 mg/g of dry wt) as compared to the other extracts. Further, oil (1250 μg/disc) and extracts (1750 μg/disc) revealed 35.33–67.66 and 18.0–53.3% antidermatophytic effect, respectively, along with their respective MIC values (62.5–500 and 250–4000 μg/ml) against Trichophyton rubrum KCTC 6345, T. rubrum KCTC 6375, T. rubrum KCTC 6352, T. mentagrophytes KCTC 6085, T. mentagrophytes KCTC 6077, T. mentagrophytes KCTC 6316, Microsporum canis KCTC 6591, M. canis KCTC 6348 and M. canis KCTC 6349. The oil also had a strong detrimental effect on spore germination as well as concentration and time-dependent kinetic inhibition of M. canis KCTC 6591.     

Antioxidant activity and ultra-performance LC-electrospray ionization-quadrupole time-of-flight mass spectrometry for phenolics-based fingerprinting of Rose species: Rosa damascena, Rosa bourboniana and Rosa brunonii

Roses are one of the most important groups of ornamental plants and their fruits and flowers are used in a wide variety of food, nutritional products and different traditional medicines. The antioxidant activity of methanolic extracts from fresh flowers of three rose species (Rosa damascena, Rosa bourboniana and Rosa brunonii) was evaluated by 1,1-diphenyl-2-picryl hydrazyl (DPPH) free-radical method. The ability to scavenge DPPH radical was measured by the discoloration of the solution. The methanolic extract from R. brunonii exhibited maximum free-radical-scavenging activity (64.5 ± 0.38%) followed by R. bourboniana (51.8 ± 0.46%) and R. damascena (43.6 ± 0.25%) at 100 μg/ml. Simultaneously, ultra-performance liquid chromatography coupled with electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) was used to study phenolic composition in the methanolic extracts from the fresh flowers of rose species. The phenolic constituents were further investigated by direct infusion-ESI-QTOF-MS/MS in negative ion mode. Characteristic Electrospray ionization tandem mass spectrometry (ESI-MS/MS) spectra with other diagnostic fragment ions generated by retro Diels–Alder (RDA) fragmentation pathways were recorded for the flavonoids. Distinct similarities were observed in the relative distribution of polyphenolic compounds among the three species. The dominance of quercetin, kaempferol and their glycosides was observed in all the three species.     

Chemical composition and antioxidant activity of essential oils and solvent extracts of Ptychotis verticillata from Morocco

The objective of this study was to characterize the chemical composition of the essential oil and extracts of Ptychotis verticillata. The antioxidative activities of this species were also evaluated to suggest it as a new potential source of natural antioxidants. Analysis of the chemical composition of P. verticillata essential oil from Morocco was carried out using GC and GC-MS. The oil was dominated by phenolic compounds (48.0%) with carvacrol (44.6%) and thymol (3.4%) as the main compounds. Plant phenolics constitute one of the major groups of components that act as primary antioxidant free radical terminators. The amounts of total phenolics and flavonoids in the solvent extracts (diethyl ether and ethyl acetate) were determined spectrometrically. Furthermore, the antioxidant activities of the essential oil and extracts were determined using a DPPH test system. The DPPH scavenging activity of extracts increased in the order ethyl acetate > ascorbic acid > diethyl ether > essential oil. Finally, a relationship was observed between the antioxidant activity potential and total phenolic and flavonoid levels of the extract.     

Antioxidant and hepatoprotective activities of five eggplant varieties

Eggplant is consumed throughout the world and varies in fruit color, shape, and size. In this study, five varieties of eggplant (purple colored moderate size, white-green colored moderate size, long green, green striped moderate size and pale-green colored small size, respectively, called SM1–SM5) were evaluated for total phenolic and flavonoid content, antioxidant activity and hepatoprotection against cytotoxicity of tert-butyl hydroperoxide (t-BuOOH) in human hepatoma cell lines, HepG2. Total phenolic content found in methanol extracts of SM1–SM5 ranged from 739.36 ± 1.59 to 1116.13 ± 7.30 gallic acid equivalents mg/100 g extract and total flavonoid content from 1991.29 ± 6.32 to 3954.20 ± 6.06 catechin equivalents mg/100 g extract. SM1 and SM2 which contained high total phenolic and flavonoid had better antioxidant activities than the other varieties. Pretreatment of HepG2 cells with 50 and 100 μg/mL of SM1–SM5 significantly increased the viability (p < 0.05) of t-BuOOH-exposed HepG2 cells by 14.49 ± 1.14% to 44.95 ± 2.72%. The antioxidant activities of the eggplant were correlated with the total amounts of phenolic and flavonoid (r = 0.5310−0.7961). Significant correlation was found between hepatoprotective activities and total phenolic/flavonoid content (r = 0.6371–0.8842) and antioxidant activities (r = 0.5846–0.9588), indicating the contribution of the phenolic antioxidant present in eggplant to its hepatoprotective effect on t-BuOOH-induced toxicity.     

Coptis chinensis inflorescence extract protection against ultraviolet-B-induced phototoxicity,and HPLC–MS analysis of its chemical composition

Cultivated Coptis chinensis inflorescence has been highly valued in Chinese tea production for many years. The main alkaloid compounds in C. chinensis inflorescence ethanolic extracts (CE) were identified by high-performance liquid chromatography–mass spectrometry. The detected compounds included jatrorrhizine (4.87 mg/g), coptisine (17.18 mg/g), palmatine (3.32 mg/g), and berberine (31.81 mg/g), as well as columbamine and epiberberine (tentatively identified). CE protective activity against ultraviolet-B (UVB)-induced phototoxicity in a mitochondria model was determined by measuring thiobarbituric acid-reactive substrates, lipid hydroperoxide, conjugated diene, 4-hydroxynonenal, and glutathione. The results showed that CE excellently inhibited UVB-induced lipid peroxidation and glutathione reduction in vitro. This photoprotective effect of CE may be caused by the presence of the abovementioned alkaloid compounds and phenolic compounds that enhances CE antioxidant activity. Therefore, CE possesses potent photoprotective property that may find valuable applications in food industries and in anti-phototoxicity formulations.     

Composition,antimicrobial activity and in vitro cytotoxicity of essential oil from Cinnamomum zeylanicum Blume (Lauraceae)

The essential oil from the bark of Cinnamomum zeylanicum Blume was analyzed by GC–MS and bioassays were carried out. Nine constituents representing 99.24% of the oil were identified by GC–MS. The major compounds in the oil were (E)-cinnamaldehyde (68.95%), benzaldehyde (9.94%) and (E)-cinnamyl acetate (7.44%). The antimicrobial activity of the oil was investigated in order to evaluate its efficacy against 21 bacteria and 4 Candida species, using disc diffusion and minimum inhibitory concentration methods. The essential oil showed strong antimicrobial activity against all microorganisms tested. The cytotoxic and apoptotic effects of the essential oil on ras active (5RP7) and normal (F2408) fibroblasts were examined by MTT assay and acridine orange/ethidium bromide staining, respectively. The cytotoxicity of the oil was quite strong with IC₅₀ values less than 20 μg/mL for both cell lines. 5RP7 cells were affected stronger than normal cells. Morphological observation of apoptotic cells indicated the induction of apoptosis at the high level of the oil, especially in 5RP7 cells. The present study showed the potential antimicrobial and anticarcinogenic properties of the essential oil of cinnamon bark, indicating the possibilities of its potential use in the formula of natural remedies for the topical treatment of infections and neoplasms.     

Chemical profile,antifungal, antiaflatoxigenic and antioxidant activity of Citrus maxima Burm. and Citrus sinensis (L.) Osbeck essential oils and their cyclic monoterpene, dl-limonene

The study deals with antifungal, antiaflatoxigenic and antioxidant activity of Citrus maxima and Citrus sinensis essential oils (EOs) and their phytochemical composition. The EOs were obtained by hydrodistillation and their chemical profile was determined through GC and GC–MS analysis. Both the EOs and their 1:1 combination showed broad fungitoxic spectrum against different food contaminating moulds. The EOs and their combination completely inhibited aflatoxin B₁ (AFB₁) production at 500 ppm, whereas, dl-limonene, the major component of EOs showed better antiaflatoxigenic efficacy even at 250 ppm. Both the oils exhibited antioxidant activity as DPPH free radical scavenger in dose dependent manner. The IC₅₀ for radical scavenging efficacy of C. maxima and C. sinensis oils were to be 8.84 and 9.45 μl ml⁻¹, respectively. The EOs were found non-mammalian toxic showing high LD₅₀ for mice (oral, acute). The oils may be recommended as safe plant based antimicrobials as well as antioxidants for enhancement of shelf life of food commodities by checking their fungal infestation, aflatoxin production as well as lipid peroxidation.     

Antioxidant,anti-microbial and antimutagenicity activities of pistachio (Pistachia vera) green hull extract

Antioxidant, anti-microbial and antimutagenicity activities of pistachio (Ahmadaghaei variety) green hull extracts (crude and purified extracts) were studied. At first, different solvents were compared for determining of the best solvent for extraction of phenolic compounds from pistachio green hull. Water and acetonitrile with 49.32 and 6.22 (mg of gallic acid equivalents/g sample) were the best and the worst solvent in the extraction of phenolic compounds, respectively. The antioxidant capacity of crude and purified extracts were assessed through ABTS assay, DPPH assay and β-carotene bleaching (BCB) method. A concentration-dependent antioxidative capacity was verified in ABTS, DPPH assays and BCB method. The anti-microbial capacity was screened against Gram positive and Gram negative bacteria, and fungi. Aqueous and purified extracts inhibited the growth of Gram positive bacteria; Bacillus cereus was the most susceptible one with MIC of 1 mg/mL and 0.5 mg/mL for the crude and purified extracts, respectively. The results of antimutagenicity test showed that phenolic compounds of pistachio green hull have antimutagenicity activity against direct mutagen of 2-nitrofluorene. The results obtained indicate that pistachio green hull may become important as a cheap and noticeable source of compounds with health protective potential and anti-microbial activity.     

Antioxidant activities of the essential oils and methanol extracts from myrtle (Myrtus communis var. italica L.) leaf,stem and flower

This study was designed to examine the chemical composition and antioxidant activity of the essential oils and methanol extracts of Myrtus communis var. italica L. leaf, stem and flower. Myrtle leaf and flower were the valuable organs for the essential oil production representing a yield of 0.61% and 0.30% (w/w), respectively. The essential oil composition of myrtle leaf and flower was characterized by high proportions of α-pinene, the main compound of monoterpene hydrocarbon class, with 58.05% for leaf and 17.53% for flower. Stem was rich in oxygenated monoterpenes, largely due to 1,8-cineole with 32.84%. The total phenol contents varied between different myrtle parts; leaf extract had higher total phenol content (33.67 mg GAE/g) than flower (15.70 mg GAE/g) and stem (11.11 mg GAE/g) extracts. Significant differences were also found in total tannin contents among different myrtle parts, representing 26.55 mg GAE/g in leaf, 11.95 mg GAE/g in flower, 3.33 mg GAE/g in stem. The highest contents of total flavonoids and condensed tannins were observed in stem (5.17 and 1.99 mg CE/g, respectively) and leaf (3 and 1.22 mg CE/g, respectively) extracts. The HPLC analysis indicated that the main phenolic class was hydrolysable tannins (gallotannins) in leaf (79.39%, 8.90 mg/g) and flower (60.00%, 3.50 mg/g) while the stem was characterized by the predominance of flavonoid class (61.38%, 1.86 mg/g) due to the high presence of catechin (36.91%, 1.12 mg/g). Antioxidant activities of the essential oil and the methanolic extract from different myrtle parts were evaluated by using DPPH radical scavenging, β-carotene-linoleic acid bleaching, reducing power and metal chelating activity assays. In all tests, methanolic extracts of different myrtle parts showed better antioxidant activity than essential oils.